I have experience of them, yes. They are great, when they work. Other than the Lefty, they are probably one of the better short travel cross country mountain bike forks if by best, you mean stiffest & lightest.
But you are considering a 'BadBoy' which is usually used on-road. In this case, a fork, headshok or not, is at best a bit of a waste of time, and at worst, a costly mistake.
The dirty secret of suspension forks, Headshok, or otherwise, is that they need regular and quite specialised maintenance, and if you don't treat them right, they suffer, and eventually die, and it's expensive to repair / replace them.
Are they any less reliable than 'normal' forks? No. Do they suffer from the same problems if left unmaintained? Yes.
If you ride on road mostly, and want comfort, go for bigger tyres and a rigid fork for simplicity & reliability.